Everyone has their own gripes. Modules are what cause me the most pain in Go - especially where they're in github and I need to fork them and now change all the code that references them. I don't know if the problems are even tractable because the way it all works is so incredibly complicated and any change would break a lot.
I would like to remove all the "magic" that's built-in for specific SCMS/repository hosting services and have something that operates in a simple and predictable manner like C includes and include paths (although obviously I don't like preprocessing so not that).
As for the language, I like the range reference idea but my own minor pet peeve is an issue with pre-assignment in if-statements etc which makes a neat feature almost useless:
// This is nice because err only exists within the if so we don't have to
// reuse a variable or invent new names both of which are untidy and have potential
// to cause errors (esp when copy-pasting):
if err := someoperation(); err != nil; {
// Handle the error
}
// This however won't work:
func doThing() string {
result := "OK"
if result, err := somethingelse(); err != nil { // result does not need to be created but err does so we cannot do this.
return "ERROR"
}
return result
}